Post History

How do you establish identity when people can change their appearance at will?

Building on the universe established in [this question][1], what happens to identity verification when someone's physical appearance and genetic code are modifiable at any time?

Review of universe rules:

 - All genetic disorders have been eliminated.  Children are tested at birth for [disorders][2] and those disorders are eliminated. Eugenics doesn't play a role here as every outward attribute is maleable.
 - Genetic manipulation is cheap, ubiquitous, and perfect (no side-effects or unintentional changes).
 - Genomes are cheap to sequence ($10/genome).
 - Gene treatments are capable of manipulating every single characteristics of a person's body, including but not limited to, hair color, eye color, skin color, facial structure, body fat distribution, height, musculature, sex.
 - Near-future (max 2025) technology levels. (Admittedly, genetic manipulation of this kind is probably not going to be available in the next 10 years, but just go with it.)
 - Genetic manipulations are highly regulated with perfect enforcement of regulations by a global regulatory body.  This doesn't preclude people from making illegal genetic changes, just the assurance that they will be caught and the changes reverted.
 - Manipulation of the brain or brain chemistry is strictly prohibited. (Sorry, schizophrenics, your time will come.)

Additional rules:

 - While the treatments are very monetarily cheap for all possible manipulations, the changes themselves can be painful and lengthy.  For example, adding two inches to your height would require time off your feet and some painkillers as your bones, tendons and muscles reform themselves to the new genetic blueprint.
 - Genetic privacy is tightly regulated with long court histories protecting a person's genome; think European privacy laws only with stronger penalties and tighter enforcement.

----------

To establish a user's identity, three different components may be used, something the user has (such as a credit card), something the user knows (PIN to a credit card) or something permanently attached to the user (fingerprints or facial recognition). Strong authentication or [two factor authentication][3] relies on having two of the three identification components.

With this new gene manipulation technology, biometric authentication no longer works the way it did. Looking at someone's picture on a drivers license or taking fingerprints no longer unequivocally establishes someone's identity.

 *What kind of technological and/or regulatory solution(s) might be used to ensure that a person's identity can be verified with 99.99999% accuracy?* (At this degree of accuracy, a misidentification will occur once in every million identification attempts)  Broader changes to society as a result of amorphous physical identities are outside the scope of this question.


  [1]: https://worldbuilding.stackexchange.com/questions/21142/how-do-you-find-a-mate-when-everyone-looks-amazing
  [2]: http://www.genome.gov/10001204
  [3]: https://en.wikipedia.org/wiki/Two-factor_authentication